The invention relates to an exercise device for developing muscles in the hand, arm, and chest by adduction or abduction of one or both hands.
Good hand strength is important in many daily, athletic, and therapeutic activities, and is directly related to the strength of the wrists, arms, and upper body. To develop hand strength, previously known hand exercisers, such as rubber or foam balls which the user holds in his palm and squeezes, allow the user to contract and then stretch his finger and hand muscles, i.e., to exercise abductor and adductor muscles. Many of such devices are referred to herein as active exercise devices. That is, the device exerts a force of its own which causes it to return to its original state. As referred to herein then, a "non-active" other hand, does not exert a force to cause the device to return to its original position. Rather, the user must exert force by abduction and adduction to move the device to different positions.
Other known active exercisers include two handles connected by a spring or other compressive force which urges the handles either away from one another for adduction, i.e, wherein a user grasps the handles from the outside and attempts to force the handles together, or toward one another for abduction, i.e., wherein a user places his thumb and fingers on the inside of either handle and attempts to force the handles apart. Another active exerciser includes two parallel rods connected to a rectangular frame, the size of which can be adjusted by placing a pin through corresponding holes in members of the frame. The rods are biased towards one another by elastic bands which provide a resistant force when the user attempts to pull the rods away from one another.